A technical issue has taken voting machines out of commission throughout all of Mercer County, N.J., and they won't be back online by the time polls close — though officials say all votes will still be counted.

Voters are being asked to fill out paper ballots and drop them in an emergency slot in the back of voting machines. While some municipal clerks initially said those would be tabulated by hand, County Clerk Paula Sollami Covello clarified to Gothamist those would be processed by the county with high-volume optical scanners once polls close.

She said tabulating Election Day votes would take longer than normal — possibly finished late overnight, but more likely stretching into days. The county wouldn't need a court order to get access to the ballots, she said.

The county's Board of Elections has also decided not to try and get the machines repaired before polls close, to avoid having voters with two different experiences — some using the emergency slots, and some not.

The paper ballots are still standard ballots, not provisional ballots. They don't require any special verification before being counted.

But that could delay calling a winner in the3rd Congressional District, where incumbent Andy Kim is fighting a challenge from Republican Bob Healey. The Cook Political Report downgraded Kim's chances from "likely Democrat" to "lean Democrat" last week, though the incumbent still retains a large fundraising advantage. The district includes most of Burlington County and portions of Mercer and Monmouth counties.

Mercer also includes part of the 12th District, where incumbent Democrat Bonnie Watson Coleman is facing a challenge from Republican Darius Mayfield.

Via social media, both the state's Republican and Democratic committees reassured residents that their votes in Mercer would count. The state Republican committee said the ballots remain in the proper chain of custody, and the Democratic committee told voters their voices would be heard.

"On behalf of our NJGOP legal counsel and election integrity team, I want to make crystal clear to the voters of Mercer County that in spite of reported problems with scanners on voting machines in Mercer County, this issue does not affect their voting experience at all," Tom Szymanski, executive director of the state GOP, said in a statement. "Voters will still enter their polling place, cast their vote, and insert the paper ballot into the machine as they normally would.

The state Democratic Committee said on Twitter it had deployed resources from its voter protection team to Mercer, "to make sure the tabulation of the vote will go smoothly, so voters in Mercer County should feel 100% confident that their vote will be counted and should make sure to get to the polls before 8 p.m."

Henal Patel of the New Jersey Election Protection Coalition said the group was continuing to monitor the situation in Mercer County as well.

"There is a system in place. We have guardrails. And you can vote by paper ballot," she said. "It will count, it is safe and secure, and you should not leave your polling place without voting."

Mail-in votes can be received up to six days after Election Day in New Jersey, which could also delay calling some tight races. Mail-in votes must be postmarked by Tuesday, or dropped off at dropboxes or polling sites by 8 p.m. Secure drop locations are listed here. Voters who requested and were sent mail-in ballots, but show up at the polls anyway will be given provisional ballots, to be counted once election officials confirm they didn’t also vote by mail.

A clerk at the county superintendent of elections' office referred Gothamist to a technician who was not authorized to speak to the press, but said it's unlikely the machines will be up and running today. Other calls to the superintendent's office, the county clerk's office and the county's board of elections haven't yet been returned.

Sollami Covello said it wasn’t yet exactly clear whether the issue had been with the machines or the printed ballots, and officials were continuing to investigate.

Mercer officials said via Facebook that poll workers were on hand to walk voters through the process, and the county Board of Elections was working with voting machine company Dominion to resolve the issue.

“No one will be disenfranchised and we are working on fixing the issue at present. It may delay results, but we will make sure everyone votes,” Sollami Covello said in an email to CNN. Calls to the clerk's office by Gothamist have not yet been returned.

At Hightstown Engine Company No. 1, the only polling place in the municipality, voters continued casting ballots despite the problems with machines, with little or no sign of difficulty on Tuesday.

The New Jersey Department of State voter hotline is 877-NJ-VOTER. The Election Protection Coalition has a statewide hotline to report any problems with voting at 866-OUR-VOTE.